Electromagnetic device



July 16,1929. E CHAPMAN I v 1,720,943

ELECTROMAGNETIC DEVICE Filed July 2, 1927 I N VEN TOR.

A TTORNEYS.

UNITED ST Fa tented July 16, 1929.

. a 11,720,943 Ares P,A-T ENT' .orrlca.

, imm CHAPMAN, for QLEVELAND, .onro, ASSIGNOB To. run Lri'rconu ELECTRIC I COMPANY, 01? CLEVELAND, orno, A con-rom'rron or 01110.

. mnc'raomenmrc msvrcn.

" a ncifuoa filed m 2, 1927. Serial n. 203,067.

The present improvements have more parequivalent ticular regard to the construction of the core, or supporting tube orbobbin, of a solenold or coil. The principle of the invention is also applicable to the construction of the plunger in such device as well .as of the core. Solid cores as well as plungers' have heretofore been made of laminations, that is, of-superimposed platesguitably secured together, to- 1 form an assembled body of-desired shape and trated in Figs. 1 and 2, it will be seen that the size. The object of the present inventionis to obtain the'efi'ect of such-a laminated metallic core or plunger without thus actually making the same or separate plates. My improved construction is also adapted for use in place of a tubular core, i. e., to'take the place of the split meal tube which is ordinarily employed in this connection. It is well known that such split metal tube is unsatisfactory in that it is difficult to maintain it of 'afixed 'diam'eterand since the ends of the bobbin are usually attached tosuch split tubular core, difliculty is encountered in assembling jthe partsin the completed device. f the foregoing To the accomplishment of;-

arid related ends, the invention, then,.con-

' sists of the'means and steps described and'particularly pointed out in the hereinafter fully claims, the annexed drawing-illiistrating but several of the various ways in which the prin ciple of theinvention may be carried out.

' In said annexed drawing Fig. 1 is a transverse section of a solenoid wherein'thewinding is mounted onv a tubular core of my presentimproved construction; .Fig. 2 is a longitudinal, i. e. axial section, of

r the same taken on 'the plane indicated by the line 22, Fig.1; Fig. 3 is a broken perspec=' tive view of the sheet or strip-of metal with accompanying insulating strip whereof my improved core is made; Fig. 4 isa perspective view of a solid core orplunger-made in accordance with my improved method, the part in question being of cylindrical form;

Fig. 5 s'imllarly illustrates such part where of general rectangular form, i. e., s ecifically of square cross-section; Fig. 6 I axial section a modified form of tubular core having a flange or shoulder at one end; Fig. 7 illustrates still another form of tubular core having a shoulder atieachend; Fig. 8 is a -,.-broken plan view and Fig. 9a sid elevation of the strips of material from which the core of-Fig. 6 is fashioned; Fig. 10 is similarly a support for an electro-magnetic' i lustrates in.

planview of the strips of material 'from which the core of Fig. 7 is fashioned; Figs. 11 and 12 are axial sections'of two forms of outer. shells designed for use in so-called ironclad, magnets, such shells being made in a fashion similar to the aforesaid cores; Fig. 13 is' an axial section of a core of a solenoid of the so-called long pull type; and Fig. 14 1s a plan view of the sheets of material from which such core is made. I 1

R.eferring to the solenoid device illusshell of desired thickness is provided. The

sheet of paper 5 issodisposed as to insulate the successive turns of the metal strip 4 from each pther and prevent a closed metallic circuit, and may be extended to permit its being wrapped one or more times-around the-completed core to' assist in insulating the coil winding 1 therefrom. As a result of the foregoing construction, a core is obtained hating the electricalcharacteristics of a split metal tube and at the same time that of a laminated core structure. Not only may such core be readily fabricated-from sheet or strip metal in the fashion described, but it also contributes to the readyassembly' of the sole- 'noid device as.a whole.

Instead of winding the strips 4 and 5 to forma tubular member, as illustrated in the caseof the core 2 just described, such strips may be Wound together to form either a solid cylindrical body 7, as shown in Fig. 4, or a rectangular body 8, as shown in. Fig. 5. Either of the latter is obviously adapted to serve as a solid laminated core or' solid laminated plunger in an electro-magnetic device.

\ WVhere it is 10 with a shoulder or flange 11 at one end, .as illustrated in-Fig. 6, this is readily accomplished by making the composite'sheets'oftwo desired to-form a tubular core different widths, asshown in Figs. 8 and 9."

In other words, when sheets such as shown in the last mentioned fi%1res are rolled-up" about a tube or. mandrel eginning at the left- I hand end of such sheets,

- be readily the narrower portion thereof will obviously be wound up last and thus provide the desired shoulder at oneend. Similarly, b making the sheets of material of the form ilustrated in Fig. 10 and then winding them up beginnin at the left-hand end, a core 12 having the f rm of a spool or bobbin, i. e., with a shoulder or flange 13 at each end thereof, is provided.

An outer shell of laminated construction for so-called iron-clad magnets may likewise described-for the fabrication of the cores and plungers of solenoids. Thus, a shell 14 having inwardly directed flanges. 15 at its respective ends may be formed from strips of material cut as shown in Fig. 10, by simply winding such strips up in the reverse direction from that observed in forming the core illustrated in Fig. 7. In case a shell 16 with an inwardly directed flange 17 at one end thereof only, as illustrated in .Fig. 12, is desired, this may be readily fashioned from strips of material cut as shown in Fig. 8, by winding such strips up beginning at the right-hand end thereof instead of the left.

My present improved construction also lends itself readily to the fabrication of the cores for so-called long pull solenoidsv in which a tapered effect is desired. Such an element 18 may be formed from a sheet cut to the shape illustrated in Fig. 14, by rolling such sheet beginning at the left-hand end thereof. The resulting element, in other words, will then have a recess 19 of conical made in the fashion-hereinbefore.

shape inthe one end thereof. By rolling up the sheet from the opposite end the element formed therefrom instead ofeing recessed will itself have a conical pointed end. Other forms may be employed embod ing the features of my invention instead of the one here explained, change being made in the form or construction, provided the elements stated by any of the following claims or the equivalent of suchstated elements be employed, whether produced bymy preferred method or by others embodyingflsteps equivalent to those stated in the following claims.

I therefore particularly point out and distinctly claim as my invention I 1. As a new article of manufacture, a core or like element for an electro-magnetic device comprising a strip. of sheet metal rolled upon itself in closely contactin turns with insulating material interposed between successive turns, said strip having-a portion extending further than the midline portion of the strip whereby the element is formed with a shoulder or flange. 2. As a new article of manufacture, a core or like element for an electro-magnetic device comprising a strip of sheet metal rolled upon itselfin closely contactin turns with insulating material interposed between successive turns, said strip having spaced p ural parallel narrow portions extensive from another portion, whereby the element is formed with corresponding shoulders or flanges.

Signed by me this 30th day of June, 1927.

EVERETT CHAPMAN." 

